research memorandum 

About: research memorandum is an academic journal. The journal publishes majorly in the area(s): Population & Empirical research. Over the lifetime, 825 publications have been published receiving 9234 citations.

Verification and validation of simulation models

Abstract: This paper surveys verification and validation of models, especially simulation models in operations research. For verification it discusses 1) general good programming practice (such as modular programming), 2) checking intermediate simulation outputs through tracing and statistical testing per module, 3) statistical testing of final simulation outputs against analytical results, and 4) animation. For validation it discusses 1) obtaining real-worl data, 2) comparing simulated and real data through simple tests such as graphical, Schruben-Turing, and t tests, 3) testing whether simulated and real responses are positively correlated and moreover have the same mean, using two new statistical procedures based on regression analysis, 4) sensitivity analysis based on design of experiments and regression analysis, and risk or uncertainty analysis based on Monte Carlo sampling, and 5) white versus black box simulation models. Both verification and validation require good documentation, and are crucial parts of assessment, credibility, and accreditation. A bibliography with 61 references is included.

Older workers motivation to continue to work: five meanings of age: A conceptual review

Abstract: Purpose: Little is known about the motivation for older workers to work and to remain active in the labor market. Research on age and motivation is limited and, moreover, conceptually diverse. In this study, we address age-related factors that influence the work motivation of older workers. More specifically, we examine how various conceptualizations of the age factor affect the direction and termination of the motivation to continue to work of older workers. Methodology: A literature review of age-related factors and motivation to continue to work. Findings: Results from 24 empirical and 9 conceptual studies indicate that most age-related factors can have a negative impact on the motivation to continue to work of older people. These findings suggest that age-related factors are important in understanding older workers' motivation to continue to work and that further research is needed to more fully understand the underlying processes that govern how these age-related factors influence the motivation to continue to work. Research limitations / implications: Based on the aforementioned findings, we were able to formulate a research agenda for future research, namely: 1) a need for a meta-analysis on age and motivation to determine the actual effect sizes, 2) additional theoretical attention to the underlying age-related processes, 3) more psychometric studies examining the operationalization and measurement of the age-related variables, and 4) additional empirical research on age-related variables and motivation. Practical implications: Age-related factors identified in this study, such as declining health and career plateaus, should be addressed by HRM policies. HRM practices that could motivate older workers to continue to work include ergonomic adjustments and continuous career development. Originality / value of paper: Research on age and motivation is limited and conceptually diverse. This paper is one of the first studies to explore the relations between different conceptualizations of age and motivation.

Perceived risk and trust associated with purchasing at Electronic Marketplaces

Abstract: Understanding consumer behaviour is of vital importance to consumer oriented e-business models today. In this paper we study the relationships between consumer perceptions of risk and trust and the attitude towards purchasing at a consumer-to-consumer electronic marketplace. Typical for electronic marketplace settings is that consumer behaviour is subject to perceptions of the selling party as well as the institutional structures of the intermediary that is operating the electronic marketplace. Building upon the well-established literature of trust we consider the concepts of institutional trust and party trust. We extend this categorization by introducing the concepts of institutional risk and party risk. We developed measurement instruments for institutional risk and party risk. All measurement scales have acceptable alphas and are unidimensional. An empirical study is conducted to explore the relationships between the risk and trust types and consumer purchase attitude. The results reveal significant, direct effects of party trust and party risk. Second order effects of institutional trust and institutional risk are investigated and reported. The paper concludes with general observations and recommendations for research and practice.

Explaining online purchase intentions: A multi-channel store image perspective

Abstract: This study is one of the few empirical works addressing the impact of offline and online store impressions on consumer online purchase intentions. Building upon the literature on store image and consumer online purchasing, we propose positive effects of online store image and suggest mixed influences of offline store image perceptions. Drawing on a sample of 630 customers of one of the largest music retail stores in the Netherlands, hypotheses are tested. The empirical results clearly support the assumed positive effect of online store image, and confirm that the influence of offline store image on online purchase intentions can be positive as well negative. We discuss the implications of our research, and conclude with directions for further research.

Games with permission structures : The conjunctive approach

Abstract: This paper is devoted to the game theoretic analysis of decision situations, in which the players have veto power over the actions undertaken by certain other players. We give a full characterization of the dividends in these games with a permission structure. We find that the collection of these games forms a subspace of the vector space of all games with side payments on a specified player set. Two applications of these results are provided. The first one deals with the projection of additive games on a permission structure. It is shown that the Shapley value of these projected games can be interpreted as an index that measures the power of the players in the permission structure. The second application applies the derived results on games, where the organization structure can be analysed separately from the production capacities of the participating players.